The cries for help came from just behind the police station in Healdsburg, a small town in Northern California.
In the parking lot outside police headquarters, officers found a naked man holding the wet, lifeless body of his 4-year-old daughter.
Gerardo Ordaz, 42, was arrested early Monday after investigators concluded that he drowned his daughter in the baptismal pool of a nearby Roman Catholic church, the Healdsburg Police Department said.
Earlier in the evening, Ordaz had been with his daughter and a 9-year-old boy in the sanctuary at St. John the Baptist Catholic Church, about one block from the police station.
Inside the house of worship, investigators say, Ordaz drowned his daughter in the foot-deep water of the baptismal pool.
"They were the only ones in the church at the time," Healdsburg police Chief Kevin Burke said. "The church leaves the doors open late on Sunday."
Police did not specify a motive but said they do not believe the death was accidental.
After Ordaz arrived about 8:30 p.m. at the police station, officers tried to revive the girl and she was rushed to a hospital. There, she was formally pronounced dead, Lt. Matt Jenkins said.
The killing was set to be the first homicide in Healdsburg since 2008, when a woman fatally stabbed her boyfriend. The town of about 11,000 people is 15 miles northwest of Santa Rosa.
The child's death stunned the parish community at St. John the Baptist, which was founded in 1860.
The church's pastor, Fr. Sean Rogers, issued a brief statement: "Sunday night, there was a tragedy in the church; a little girl lost her life.
"When police finish the investigation, we will know more," Rogers said. "In the meantime, please pray for the family, and the parish community."
Ordaz was booked on suspicion of murder and was being held without bail in the Sonoma County jail.
Prosecutors charged him with one count of murder and he was scheduled to appear Tuesday afternoon in court for his arraignment, according to jail records.